Keeping weight off is notoriously difficult, and a small new study sheds light on why it's so hard: To truly keep the pounds away, people may have to deal with feelings of increased hunger for the rest of their lives. The study, from researchers in Norway, involved 34 patients with "severe" obesity who weighed 275 lbs. (125 kilograms), on average, at the study start. Participants were able to keep their weight off for this two-year period, but their levels of the hunger hormone ghrelin increased, and those increases lasted for the entire study. read more